agrier@poofygoof.com (Aaron J. Grier) writes:
> cpu0: family 6 model 1 step 9
> cpu0: Intel Pentium Pro (686-class)
>
> is the L2 cache internal or external?

The PPro is a two chip "hybrid" IC with the L2 cache chip mounted in
the same ceramic case with the CPU.

I seem to recall some of my systems had bios settings for turning on
cache ECC.  Perhaps that can help narrow things down?  

Also re-seating the CPU couldn't hurt.

-wolfgang